Circular knitting machine

ABSTRACT

A circular knitting machine. The apparatus includes: a knitting cylinder; a bed for supporting the knitting cylinder; a plurality of cam blocks; a dial or double cylinder for forming a rib stitch; and a reduced height cam for forming a tuck stitch on the cylinder needle. Also, in the preferred embodiment, the present invention includes an actuator for selectively disengaging the second feed needle clearing cam. The present invention also includes a rib knit, tubular article having at least two rib stitches per cylinder stitch section.

BACKGROUND OF THE INVENTION

[0001] (1) Field of the Invention

[0002] The present invention relates generally to circular knittingmachines and, more particularly, to a circular knitting machine forknitting a rib-knit tubular article, such as a sock, which hassignificantly increased cross-stretch.

[0003] (2) Description of the Prior Art

[0004] Socks are usually made on cylinder sized knitting machinesgenerally in 3-5 inch cylinder width category. These machines producesocks which provide very good fit in the foot, but do not provideadequate cross-stretch in the ankle and leg portion for individuals whohave larger calves or specific medical needs. The mid-calf sock found inthe prior art is very difficult for individuals with large calves towear. Specifically, if the sock fit in the foot portion, generally thetop portion for the larger calved person was much too tight. Thus, theprior art socks did not have a significant amount of cross-stretch, sothat the wider girth calf would become a very uncomfortable fit.

[0005] Another area of difficulty in prior art was how the standard sockmay fit a diabetic. Diabetics tend to have significant foot problems andhaving a sock that fits well and is comfortable in the foot, ankle andthe leg portion is extremely important to a diabetic. The sock needs tobe non-binding, but it also needs to stay up and not fall and end up atthe ankles. Specifically, diabetics require socks with very loose ankleand leg portions because significant compression in those areas is verypainful for diabetics who normally have very sensitive skin. Standardsocks, if they are loose enough in the ankle and calf area to becomfortable, tend to fall down and not stay up on the calf. If theystayed up, they tended to be too tight in the body of the sock and thecompression caused by the elasticity of the sock was painful to thediabetic.

[0006] For diabetics, it is necessary that socks fit particularly wellin the foot area and have sufficient elasticity in the ankle and legarea, so that they stay up without causing excess compression and stressagainst the ankle and leg. In dress socks, in the mid-calf length, it isnecessary that the sock fit the foot and has sufficient elasticity tostay up above the calf without unnecessary binding and without excessfabric. This is particularly true in mid-calf socks for persons withlarger than average calves.

[0007] There is a need therefore to provide adequate and comfortablyfitting socks for diabetics without causing any binding or pressure inthe ankle or leg portion of the sock. It is also necessary in themid-calf dress sock design that the mid-calf sock comfortably fits thefoot and at the same time has sufficient elasticity to fit the ankle andthe larger than average calf without binding and having excess fabric.However, conventional circular knitting machines are unable to create astitch with the necessary variation in stretch.

[0008] Thus, there remains a need for a new and improved circularknitting machine for knitting a rib-knit tubular article, such as asock, which includes means for knitting a tuck stitch on the cylinderneedle to provide significantly increased cross-stretch while, at thesame time, includes means for preventing the fabric from snagging on theneedles.

SUMMARY OF THE INVENTION

[0009] The present invention is directed to a circular knitting machine.The apparatus includes: a knitting cylinder; a bed for supporting theknitting cylinder; a plurality of cam blocks; means for forming a ribstitch; and means for forming a tuck stitch on the cylinder needle. Inthe preferred embodiment, the means for forming the cylinder tuck stitchincludes: means for lowering the second feed clear cam; and a fabricseparator for preventing the fabric from snagging on the needles. Also,in the preferred embodiment, the present invention includes means forselectively disengaging the second feed needle clearing cam.

[0010] In the preferred embodiment, the means for lowering the secondfeed clear cam include reduction of the cam height. Also, the fabricseparator may include an air blast directed at the fabric, which may beselectively activated. Alternatively, the fabric separator may includeincreased angle separation between an empty needle and the stitchformation. Preferably, the increased angle is greater than about 20degrees. Also, the means for forming a tuck stitch on a cylinder needlemay be either a single revolution or the apparatus may skip arevolution.

[0011] The means for selectively disengaging the second feed needleclearing cam may further include a second feed needle clearing cam andan actuator connected to the second feed needle clearing cam. In thepreferred embodiment, the actuator includes a rod connected to the drumof the knitting machine.

[0012] The knitting cylinder may further include at least two feed camsor further includes multiples of two (e.g. 4, 6, etc.). The plurality ofcam blocks form the cylinder tuck stitch. The means for forming the ribstitch is a dial or a double cylinder.

[0013] The present invention also includes a rib knit, tubular article.In the preferred embodiment, the knitted tubular article includes: atleast two rib stitches per cylinder stitch section. In the preferredembodiment, the cylinder section further includes a flat knit section.

[0014] The flat knit section may further include a foot including aheel, instep, a sole and a toe. The flat knit section may furtherinclude a cushioned portion, wherein the cushion portion includes a fullcushion portion, a half cushion portion or a random cushion selection.

[0015] In the preferred embodiment, the knitted tubular article alsoincludes one rib per cylinder per stitch section. The rib stitches percylinder stitch section further include cross stretching greater thanabout 130%. Also, the rib stitches per cylinder stitch section furtherinclude length stretch, which is substantially the same as one to one.

[0016] Accordingly, one aspect of the present invention is to provide acircular knitting machine. The apparatus includes: a knitting cylinder;a bed for supporting the knitting cylinder; a plurality of cam blocks;means for forming a rib stitch; and means for forming a tuck stitch onthe cylinder needle.

[0017] Another aspect of the present invention is to provide in acircular knitting machine, the apparatus including: a knitting cylinder;a bed for supporting the knitting cylinder; a plurality of cam blocks;and means for forming a rib stitch the improvement comprising: means forforming a tuck stitch on the cylinder needle, the means including: meansfor lowering the second feed clear cam; and a fabric separator forpreventing the fabric from snagging on the needles.

[0018] Still another aspect of the present invention is to provide acircular knitting machine. The apparatus includes: a knitting cylinder;a bed for supporting the knitting cylinder; a plurality of cam blocks;means for forming a rib stitch; means for forming a tuck stitch on thecylinder needle, the means including: (i) means for lowering the secondfeed clear cam; and (ii) a fabric separator for preventing the fabricfrom snagging on the needles; and means for selectively disengaging thesecond feed needle clearing cam.

[0019] Still one more aspect of the present invention is to provide arib knit, tubular article. The knitted tubular article includes: atleast two rib stitches per cylinder stitch section; one rib per cylinderper stitch section; and a flat knit section.

[0020] These and other aspects of the present invention will becomeapparent to those skilled in the art after a reading of the followingdescription of the preferred embodiment when considered with thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a perspective view of a circular knitting machineconstructed according to the present invention;

[0022]FIG. 2 is a front elevational view of the apparatus as shown inFIG. 1;

[0023]FIG. 3 is a rear elevational view of the apparatus as shown inFIG. 1;

[0024]FIG. 4 is an enlarged perspective view of the reduced cam height;

[0025]FIG. 5 is an enlarged side elevational view of the reduced camheight shown in FIG. 4 illustrating the raising cam of the presentinvention;

[0026]FIG. 6 is cross-sectional view of a knitted tubular articleproduced by the present invention containing the unique cylinder tuckstitch of the present invention;

[0027]FIG. 7 is a perspective view of the tubular knitted article,namely a sock; and

[0028]FIG. 8 is a perspective view reflecting the various sections ofthe tubular knitted sock.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] In the following description, like reference characters designatelike or corresponding parts throughout the several views. Also in thefollowing description, it is to be understood that such terms as“forward,” “rearward,” “left,” “right,” “upwardly,” “downwardly,” andthe like are words of convenience and are not to be construed aslimiting terms.

[0030] Referring now to the drawings in general and FIG. 1 inparticular, it will be understood that the illustrations are for thepurpose of describing a preferred embodiment of the invention and arenot intended to limit the invention thereto. As best seen in FIGS. 1 and2, a circular knitting machine, generally designated 10, is shownconstructed according to the present invention. The circular knittingmachine 10 includes the major sub-assemblies as follows: a creel (notshown), a knitting cylinder 12, a bed for supporting the knittingcylinder 14, a plurality of cam blocks 16, a means for forming the ribstitch 20, and a plurality of needles (not shown).

[0031] According to the present invention, a circular knitting machineutilized to knit hosiery, in particular rib knit socks, is modified toproduce a special stitch which provides for cross-stretch in the fabricwhich is greater than 130% of the fabric, while at the same time,providing virtually no stretch in the length of the fabric. Thecross-stretch elasticity provided by the modified circular knittingmachine 10 has unique application in rib knit tubular articles, inparticular, socks.

[0032] Knitting cylinder 12 contains at least two feed cams. These feedcams are included within the knitting cylinder 10 in multiples of two(e.g. 4, 6, etc.). The knitting cylinder 12 also contains a plurality ofcam blocks 16.

[0033] Referring to FIGS. 3 and 4, a means for selectively disengaging asecond feed needle clearing cam 26 and a second feed needle clearing cam30 are shown. The second feed needle clearing cam 30 also includes anactuator comprising a rod connector 32 connected to drum 34 of theknitting machine.

[0034] Referring to FIG. 5, the knitting cylinder 12 also contains meansfor forming a rib stitch 18. The means for forming a rib stitch 18 mayeither include a dial or a double cylinder.

[0035] In the present invention, the circular knitting machine 10 alsocontains a means for forming a tuck-stitch 20 with the cylinder needle.In the preferred embodiment, this includes a means for lowering thesecond feed jack cam 22. Also, in the preferred embodiment, the meansfor lowering the second feed jack cam 22 is a reduced height cam asdepicted in FIG. 5. The jack cam raises just high enough under speedthat it may raise too high and lose a stitch, thereby making a hole or“pick-looking” defects. In the preferred embodiment, the top of the jackcam is ground down about 0.090 inches.

[0036] The jacks are at the bottom part of the cylinder. They arenormally selected on the first feed and what they select on the firstfeed comes through on the second feed. If the jack goes any higher thantuck, in other words, if it raises high enough that the yarn actuallyfalls off of the latch, then a bad stitch or a hole is formed instead ofa tuck stitch.

[0037] When it gets to the jack cam, if it is a knitted stitch, then theneedle clearing cam is in and when it comes over to the needle clearingcam, the jack cam picks it all the way up and makes a knitted stitch butby pulling that cam out, then a cylinder tuck stitch is made. If thejack cam is not low enough it just makes bad stitches. While the machinecould probably run a very tight stitch while leaving the jack cam at astandard height and make a tuck stitch, as cross stretch is increasedthe stitches pull a lot longer stitch and it will probably shed off ofthe latches.

[0038] Typically, tuck stitches are not made on rib machine. Most ribmachines have the needles raised up a little bit higher so the yarn willcatch in the needles better. However, in the present invention, theneedles are put in on a knitted position and when the yarn is droppedin, the needles are very high when the needles catch the yarn, and justas soon as the needles start pulling that yarn down, then the cam ispulled out and the needles go into a tuck position so that the yarn inunder the needles.

[0039] The circular knitting machine 10 may further include a fabricseparator 24 to prevent the fabric from being snagged by the needles andbunching the fabric. In the preferred embodiment, the fabric separator24 is an air blast directed at the fabric, which is selectivelyactivated at the appropriate time in the prescribed knitting cycle. Thefabric separator 24 may also be accomplished by an increased angle ofseparation between an empty needle and the stitch formation. Thisincreased angle should be greater than about 20 degrees.

[0040] In operation, formation of the tuck-stitch 28 on the cylinderneedle is made on a single revolution. After the formation of eachtuck-stitch 28, the cylinder needle commences another revolution to formthe tuck-stitch 28. Thus, according to the present invention, therib-knit tubular article fabricated includes at least two rib stitches42 per cylinder stitch 44 and each cylinder section further includes aflat knit section 46. This results in substantially higher cross-stretchsince there are 2 rib stitches for each cylinder tuck stitch, as bestseen in FIG. 6.

[0041] The stitch for the dial and cylinder needles are cleared on thefirst feed. The second feed clears the stitch on the dial needle butonly takes on yarn on the cylinder needle resulting in two courses ofyarn. By having two feeds or multiples of two, the cylinder tuck stitchcan be formed on the same revolution. If it had four feeds, two tuckstitches, it could be formed on the same revolution. The dial needle ismaking two courses per revolution but by not shedding the cylinderstitch on the second feed, the cylinder needles are only making onecourse.

[0042] Referring to FIGS. 7 and 8, the rib knit tubular article 40 ofthe preferred embodiment is depicted. The rib knit tubular article 40 isa sock and is shown with the various sections of the sock 40. The foot50 of the sock 40 is indicated as well as the heel 52, the instep 54,the sole 56, and the toe 58. The cushion portion 62 of the sock 40 isfurther depicted in FIG. 8.

[0043] In the preferred embodiment, the reduced height cam 22 as shownin FIG. 5 provides the means for forming the cylinder tuck stitch 28.The cylinder tuck stitch 28 is formed by having at least two ribstitches per cylinder stitch 42 and one rib per cylinder stitch 44combined with the flat knit stitch 46 as depicted in FIG. 6. Thecombination of this tuck-stitch produces a cross-stretch in the fabricwhich is greater than 130% of the fabric while at the same time,maintaining a length stretch which is substantially the same as one toone.

[0044] A sock produced by the present invention also has a significantlygreater “relaxed width” for the same cylinder size, knitting machine.“Relaxed width” is the measurement usually taken of the rib portion ofelastic containing socks as a way of measuring the amount of tension inthe sock after it has been taken off the knitting machine. For aconventionally knitted rib sock on a 4 inch cylinder machine, therelaxed width would be between about 2½ and 3 inches. However, therelaxed width of a knitted sock according to the present invention wouldbe between about 3 and 4 inches for the same cylinder size. Thus, forthe same cylinder size, the relaxed width of the rib portion of a sockproduces according to the present invention is greater than betweenabout 120% and 130% than a conventionally knitted sock on the same sizecylinder and, preferably, may be greater than about 150%.

[0045] Certain modifications and improvements will occur to thoseskilled in the art upon a reading of the foregoing description. By wayof example, older single feed machines could be modified to make theknitted article of the present invention by skipping every otherrevolution. However, this would be much less efficient than the multiplefeed machine of the present invention, which does not have to skip arevolution. Also, while in the preferred embodiment, the second feedjack cam is physically and permanently lowered, it could also bemechanically lowered in some newer machines. It should be understoodthat all such modifications and improvements have been deleted hereinfor the sake of conciseness and readability but are properly within thescope of the following claims.

We claim:
 1. A circular knitting machine, said apparatus comprising: (a)a knitting cylinder; (b) a bed for supporting said knitting cylinder;(c) a plurality of cam blocks; (d) means for forming a rib stitch; and(e) means for forming a tuck stitch on the cylinder needle.
 2. Theapparatus according to claim 1, wherein said circular knitting machinefurther includes a means for selectively disengaging the second feedneedle clearing cam.
 3. The apparatus according to claim 2, wherein saidmeans for selectively disengaging the second feed needle clearing camfurther include a second feed needle clearing cam and an actuatorconnected to said second feed needle clearing cam.
 4. The apparatusaccording to claim 3, wherein said actuator includes a rod connected tothe drum of said knitting machine.
 5. The apparatus according to claim1, wherein said knitting cylinder further includes at least two feedcams.
 6. The apparatus according to claim 5, wherein said feed camsfurther include additional feed cams in multiples of two.
 7. Theapparatus according to claim 1, wherein said plurality of cam blocksforms said cylinder tuck stitch.
 8. The apparatus according to claim 1,wherein said means for forming said rib stitch is a dial.
 9. Theapparatus according to claim 1, wherein said means for forming a ribstitch is a double cylinder.
 10. In a circular knitting machine, saidapparatus including: a knitting cylinder; a bed for supporting saidknitting cylinder; a plurality of cam blocks; and means for forming arib stitch, the improvement comprising: means for forming a tuck stitchon the cylinder needle, said means comprising: (a) means for loweringthe second feed jack cam; and (b) a fabric separator for preventing thefabric from snagging on the needles.
 11. The apparatus according toclaim 10, wherein said means for lowering the second feed jack caminclude reduction of the cam height.
 12. The apparatus according toclaim 10, wherein said fabric separator further includes an air blastdirected at the fabric.
 13. The apparatus according to claim 12, whereinsaid air blast is selectively activated.
 14. The apparatus according toclaim 10, wherein said fabric separator includes increased angleseparation between an empty needle and the stitch formation.
 15. Theapparatus according to claim 14, wherein said increased angle is greaterthan about 20 degrees.
 16. The apparatus according to claim 10, whereinsaid means for forming a tuck stitch on a cylinder needle is performedin a single revolution for a multiple feed knitting machine.
 17. Theapparatus according to claim 10, wherein said means for forming a tuckstitch on a cylinder needle includes skipping a revolution beforeforming a second cylinder stitch for a single feed knitting machine. 18.A circular knitting machine, said apparatus comprising: (a) a knittingcylinder; (b) a bed for supporting the knitting cylinder; (c) aplurality of cam blocks; (d) means for forming a rib stitch; (e) meansfor forming a tuck stitch on the cylinder needle, said means including:(i) means for lowering the second feed jack cam; and (ii) a fabricseparator for preventing the fabric from snagging on the needles; and(f) means for selectively disengaging the second feed needle clearingcam.
 19. The apparatus according to claim 18, wherein said means forselectively disengaging the second feed needle clearing cam furtherinclude a second feed needle clearing cam and an actuator connected tosaid second feed needle clearing cam.
 20. The apparatus according toclaim 19, wherein said actuator includes a rod connected to the drum ofsaid knitting machine.
 21. The apparatus according to claim 18, whereinsaid knitting cylinder further includes at least two feed cams.
 22. Theapparatus according to claim 21, wherein said feed cams further includeadditional feed cams in multiples of two.
 23. The apparatus according toclaim 18, wherein said plurality of cam blocks forms said cylinder tuckstitch.
 24. The apparatus according to claim 18, wherein said means forforming said rib stitch is a dial.
 25. The apparatus according to claim18, wherein said means for forming a rib stitch is a double cylinder.26. The apparatus according to claim 18, wherein said means for loweringthe second feed clear cam include reduction of the cam height.
 27. Theapparatus according to claim 18, wherein said fabric separator furtherincludes an air blast directed at the fabric.
 28. The apparatusaccording to claim 27, wherein said air blast is selectively activated.29. The apparatus according to claim 18, wherein said fabric separatorincludes increased angle separation between an empty needle and thestitch formation.
 30. The apparatus according to claim 29, wherein saidincreased angle is greater than about 20 degrees.
 31. The apparatusaccording to claim 18, wherein said means for forming a tuck stitch on acylinder needle is a single revolution.
 32. The apparatus according toclaim 18, wherein said means for forming a tuck stitch on a cylinderneedle includes skipping a revolution before forming a second cylinderstitch for a single feed knitting machine.
 33. A method for forming atubular knit article on a circular knitting machine, said apparatushaving a knitting cylinder; a bed for supporting said knitting cylinder;and a plurality of cam blocks, said method comprising the steps of: (a)forming a rib stitch; and (b) forming a tuck stitch on the cylinderneedle.
 34. A method for forming a tubular knit article on a circularknitting machine, said apparatus having a knitting cylinder; a bed forsupporting said knitting cylinder; and a plurality of cam blocks, saidmethod comprising the steps of: (a) forming a rib stitch; and (b)forming a tuck stitch on the cylinder needle, wherein said step forforming a tuck stitch on the cylinder needle includes: (i) lowering thesecond feed jack cam; and preventing the fabric from snagging on theneedles.
 35. A method for forming a tubular knit article on a circularknitting machine, said apparatus having a knitting cylinder; a bed forsupporting said knitting cylinder; and a plurality of cam blocks, saidmethod comprising the steps of: (a) forming a rib stitch; (b) forming atuck stitch on the cylinder needle, wherein said step for forming a tuckstitch on the cylinder needle includes: (i) lowering the second feedjack cam; and preventing the fabric from snagging on the needles; and(c) selectively disengaging the second feed needle clearing cam.
 36. Arib knit, tubular article, said knitted tubular article comprising: atleast two rib stitches per cylinder stitch section.
 37. The knittedtubular article according to claim 36, wherein said cylinder sectionfurther includes a flat knit section.
 38. The knitted tubular articleaccording to claim 37, wherein said flat knit section further includes afoot.
 39. The knitted tubular article according to claim 38, whereinsaid foot further includes a heel, an instep, a sole and a toe.
 40. Theknitted tubular article according to claim 37, wherein said flat knitsection further includes a cushion portion.
 41. The knitted tubulararticle according to claim 40, wherein said cushion portion includes afull cushion portion.
 42. The knitted tubular article according to claim40, wherein said cushion portion includes a half cushion portion. 43.The knitted tubular article according to claim 40, wherein said cushionportion further includes a random cushion selection.
 44. A rib knit,tubular article, said knitted tubular article comprising: (a) at leasttwo rib stitches per cylinder stitch section; and (b) one rib percylinder per stitch section.
 45. The knitted tubular article accordingto claim 44, wherein said rib stitches per cylinder stitch sectionfurther include cross stretching greater than about 130%.
 46. Theknitted tubular article according to claim 44, wherein said rib stitchesper cylinder stitch section further include length stretch which issubstantially one to one.
 47. A rib knit, tubular article, said knittedtubular article comprising: (a) at least two rib stitches per cylinderstitch section; (b) one rib per cylinder per stitch section; and (c) aflat knit section.
 48. The knitted tubular article according to claim47, wherein said flat knit section further includes a foot.
 49. Theknitted tubular article according to claim 48, wherein said foot furtherincludes a heel, an instep, a sole and a toe.
 50. The knitted tubulararticle according to claim 47, wherein said flat knit section furtherincludes a cushion portion.
 51. The knitted tubular article according toclaim 50, wherein said cushion portion includes a full cushion portion.52. The knitted tubular article according to claim 50, wherein saidcushion portion includes a half cushion portion.
 53. The knitted tubulararticle according to claim 50, wherein said cushion portion furtherincludes a random cushion selection.
 54. The knitted tubular articleaccording to claim 47, wherein said rib stitches per cylinder stitchsection further include cross stretching greater than about 130%. 55.The knitted tubular article according to claim 47, wherein said ribstitches per cylinder stitch section further include length stretchwhich is substantially one to one.
 56. A rib knit, tubular sock, saidknitted tubular sock having a relaxed width of between about 120% and130% than a conventionally knitted sock on the same size cylinder. 57.The sock according to claim 56, wherein the relaxed width of said sockis between about 3 and 4 inches and the relaxed width of saidconventionally knitted sock on the same size cylinder is between about2½ and 3 inches.
 58. The sock according to claim 57, wherein said sockis knitted on a 4 inch cylinder.
 59. A rib knit, tubular sock, saidknitted tubular sock having a relaxed width of greater than about 150%than a conventionally knitted sock on the same size cylinder.